Try going into one that says "new". Then hit back. It will say new still. It will show new until it is read and when you read it and go "back" it's as if you never read it. Try using the forum jump or the line above the thread that looks like this:Yup, always logged in. And I do use the back button, but even when I leave and come back hours later they still show as new.
I'll try the .tmp files thing